An illiterate girl from the slums of Uganda became an internationally ranked chess champion. So of course there is a Disney movie. But director Mira Nair has not made the usual feel-good underdog story. It is a wonderfully rich depiction of a family and a culture, as complex in its way as a master-level chess game with intricate moves by many pieces with different strengths and vulnerabilities.
At the center of the story is Harriet (Lupita Nyong'o of "12 Years a Slave"), a young widow with...